Automatic surgical mallet



Dec. l5, 1931. D. REITER AUTOMATIC` SURGICAL MALLET Filed Nov. l, 1929 Patented Dec. 1s, Y1931 UNITED vSTATES DAVID REITER, or WooDsrDE, NEwYonx AUTOMATIC SURGICAL MALLET Appuoaupn mea November 1, 1929, 'serial No. 404,079.

The invention relates to surgical instruments and has for its general obJect the provision of a novel device for use by dent1sts, oral, throat and nose, and other surgeons for cutting bone in a simplified, 'convenient and less repulsive and` nerve shocking manner than by ordinary methods. Y l

t An important object of the invention is the provision of an automatic mallet for this purpose provided interiorly with impact producing means which is readily operable and by means of which a blow of a redetermined force may be applied to the one', the device being operable by'onehand and making the services of an "assistant unnecessary.

Another object `of the invention is to rovide an instrument of this character in w ich the force of the blow is obtained by spring pressure. v ,A

A further Objectis to provide a-Inallethav-v ing very simple means which maybe readily adjusted for the purpose of*` varying the length of the stroke, and consequently the force, of the impact producing member so that different conditions may be met. Y

`Still another object islto provide a device of this character in which' all of the parts are readily separable incase ofany necessity for making repairs or replacements.

An additonal obJect is to provide a mallet which will be inexpensive to manufacture, easy to use and keep clean, positive in action, eilicient and durable in service, and a general improvement in the art,

To the attainment of the foregoing and other objects and advantages,the invention preferably consists in the details o construction and the arrangement and combination of parts to be hereinafter more fully described and claimed, `and illustrated in the accompanying drawings in which: 'A

Figure 1 is a` longitudinalV section'through the device,v` V

Figure 2 is a portion broken away and in section to lillustrate the position of the parts when the im pact producing" member is released, and Y 3-3 of Figure 1. f i n Referring more particularly to the drawside'elevationl thereof with aV gure 3 is a cross section taken onfthe Aline ings .I have shown the device as comprising an elongated preferably cylindrical barrel 1() to one end oflwhich 1sl secured, as by threading, a guide member" 11 which carries the plunger 12, this plunger being slidable withinthe bore 13 and havin its movement limited by a stop screw 14 o the grub t pe which extends throughthe reduced thi-ea edjportion 15` of the guide 11 and into a recess or cutaway portion 16 in the plunger. This plunger is adapted to be reciprocated by impact and for this reason its inner end is shown as provided with a suitably `attached impact receiving head 17 which also `constitutes `an abutmentfor one end of a coil spring 18 which has its other 'y end abutting against the inner end of the guide 11, this spring acting normally to'retract the plunger or to hold it at the inwardlimit of'its movement. The exact tool 1 9fused 4is a matter to be determined by the requirements of the particular case andin actual practice it is probable that a plurality of bits, chisels,

gouges, elevators, orV other tools would be ,Y

provided as `part of the equipmentv so that any selected one maybe connected with or mounted uponthe plunger 12.

Slidably mounted Within the intermediate portionof the barrel 10 is a hammer 20, likei wise preferably of cylindrical form, urged toward the plunger 12 by a coil spring 21 abutting against one end of the hammer in encircling relation to a reduced extension 22 thereon and also abutting against the inner face of the end wall of a ca 23 screwed on to r:

the barrel. Clearly, by ad]usting the cap, by turning it in one direction or the other, the degree of pressure exerted by the sprmg 2,1

against the hammer may be varied, this Vbei ment. A

The operating means is here disclosed as comprising alsle'eve 25 of'cylindrlcal form surrounding and slidable upon the barrel,

this sleeve being equipped :with a preferably double ended finger piece or gripping member 26 held in place by any suitable means and adapted to be engaged by any desired two of the operators fingers so that the sleeve may be moved toward the saddle member 24. This sleeve is normally urged toward the bit end of the device by a coil spring 27 which surrounds the Hbarrel and .which is enclosed within a hoodi28` suitably secured upon the barrel, one end of this spring abutting against the inside of the hood andthe ot'hera'gainst' the adjacent end of the sleeve 25 as clearly illustrated in Figure l. Y

The hammer 2O is formed with a longitu dinally extending groove*- 29 withiny which isv located a, longitudinally curved or bowed. leaf.l springA 30 which is held in place. by any suitable means such, for instance,. as a., screw 31 passing through one end` and. threaded into -the hammer. This spring; 30 is adapted to cooperate with and be engaged bj the inner end of .a screw 32, likewise pre erably of the grub type whichscrew is threaded throughone side of the` sleeve 25 andprojeets into and is movable along a slot 332m lone-,side ofthe barrel.

This screw32. is in obstructing relation to the endol the spring 30v so that when the lingen grips26ia're grasped .and the sleeve 25 pnlledtoward thesaddle member 24 the screw 321 willl'engage the spring 30 and move the hammer 20 longitudinally 'within the barrel IOfto effect. compression of they spring 2l, the stored-up energy ofV which is subsequently employed for forcing the hammer 20`into en-V gagementwiththe head 17 for delivering Vthe desired; blow tothe plunger I2 and conseq uently the-"bit 19. Threaded through one side. of the barrel `and normally covered by the, sleeve 25' is a' screw 34', or Vother equiva lenti adjustable stop,.located inthe path of movement of the spring 30 and operating to force the spring 30 inwardly or toward Vthe longitudinal axis ofthe barrel upon retraction of the-hammer so that this leaf spring 30 will be forced' out ofengagement with the Vscrew 32, thus permitting t'hefspring' 2l to force the hammer 20 in the opposite direction so that it will strike a sharp blow upon the head 17` of the plunger. Clearly, the force will be transmitted through the plunger 12 to the bit 19l By adjusting the screw 34 so that it will project into the barrel' to a greater or less extent, it is apparent that itis possible to vary or regulate the length of the retrac- Ation stroke ofV the hammer, it-being clear that when the screw 34 is caused to project farther into the barrel' it'will the sooner engage the spring'3()` and force itlout of engagement with the screw 32thereby shortening the retraction stroke. It should also beunderstood that the same eiecty can b e accomplished by adjusting the screw 32 to shorten the extent of ltsiprojection in t'ofthe barrel.A This latter mentioned adjustment is probably the more convenient to resort to as the screw 32 is always exposed whereas the screw 34 is intended to be normally covered by the sleeve 25. However, for the sake of clearness, both adjustments have been described.

Assuming that the cap 23 has been properly adjusted to give the desired pressure upon the hammer 20, and that adjustment of either or both of the screws 32 and 34 has been effected Vto give the hammer the desired and proper ,stroke,thedeviee\is used as follows: The instrument is taken in the hand with any two fingers engaging the grips 26 and with the base of the thumb engaging upon the saddle member 24F.A The operator then places the chiselY or other cutting tool against. the bone to be cut and contracts hishand'y to slide the sleeve 25 towardthe saddle member 24. The screw 32.will first. engage against the end of the spring 30A and cause they hammer 20 to move with .the sleeve, the spring 2l being progressively compressed during the movement. l As the springl 30 rides under or against thefscrew 34 it willbe forced off from the screw 32asclearly indicated in Figure 2, thereby permitting the spring 2l to, expand and force thehannner 20, sharply againstthe head 17 of the plunger, the, plunger being then. forced, out againstv the resistance ofv the springA 18.. This blow is of course transmittedthroughthe bit against thebone intheintended manner.. The outward movement of the bit .may be. describedas relative for the reason that the bit is actually held against the bone,l the result being that at the moment of' impact the entire instrument reeoils. After each. of. such` blows the operator releases thecontraction of the muscles in his handA and permits the spring 27 to move the sleeve 25,l carrying the grips` 26,` toward the bit end. The next strokeis accomplished by again contractingV thehand and moving the lsleeve asabove described. As many strokes as necessary may be given and the operation of cutting the bone is accomplished step by step as additional pieces of bone are out.

From the foregoing description and astudy ofthedrawings-itwill be apparent that I have thus provided a very simply constructed, inexpensive and easily operated and adjusted device for the purpose specified which will eficientlyper'f'orm alllthe functions for. which itis intended- Itis `believed that the construction, operation and vadvantages will be readily' apparent to, one skilled in the art without further explanation. r

While I have shown, and described thepreferred embodiment of the invention, it should be 4understoodthatv the disclosure is merely an excmpliica-tion of the principles involved as tute no departure from the spirit of the invention or the scope of the claims hereunto appended.

Having thus described the invention I claim:

l. In an automatic surgical mallet, a barrel, a spring retracted plunger slidable in one end thereof carrying a bit, a hammer slidable within the barrel formed in one side with a groove, a spring within the barrel engaging and compressible by saidhammer upon movement of the latter away from the plunger, a leaf spring secured at one end within the groove in the hammer, a sleeve surrounding the barrel and slidable therealong and equipped with gripping means, the barrel having a slot covered by the sleeve, a stop element carried by the sleeve and projecting into the slot and groove in obstructing relation to said leaf spring for locking the sleeve and the hammer together for movement away from said plunger, and means within the barrel and entering saidgroove and enga-geable by said leaf spring for moving the latter out of engagement with said stop element. v

2. In 'an automatic surgical mallet, a barrel, a spring retracted plunger slidable in one end thereof carrying a bit, a hammer slidable within the barrel, a spring within the barrel engaging and .compressible by said hammer upon movement of the latter v away from the plunger, a leaf spring carried by the hammer, a sleeve surrounding the barrel and slidable therealong and equipped with gripping means, a stop element carried by the sleeve -and projecting into the barrel 4. In an automatic surgical mallet, a barrel, a spring retracted plunger slidable in one.

end thereof-carrying a bit, a hammer slidable within the barrel, a spring within the barrel engaging and compressible by said hams mer upon movement of the latter away from the plunger, a leaf spring carried by the hammer, a sleeve surrounding the barrel and slidable therealong and equipped with gripping means, a stop element carried by the sleeve and projecting into `the barrel in obstructing relation to said leaf spring for locking the sleeve and the hammer together for movement away from said plunger,

means within the barrel engageable by said 1f leaf spring for holding the latter out of engagement Withsaid stop element, and means for adjusting the initial compression of said hammer engaging spring.

In testimony whereof I aiiix my signature.

DAVID REITER.

in obstructing relation to said leaf spring v.

for locking the sleeve and the hammertogether for movement away from said plunger, and means within the barrel engageable by said leaf spring for holding the latter out of engagement'with said stop element, said stop element being adjustable whereby its degree of projection into the barrel may be varied.

3. In an automatic surgical mallet, a barrel, a spring retracted plunger slidable in one end thereof carrying a bit, Va hammer slidable within the barrel, a spring within the barrel engaging and compressible by said hammer upon movement of the latter away from the plunger, a leaf spring carried by the hammer, a sleeve surrounding the barrel and slidable therealong andequipped with gripping means, a stop element carried by the sleeve and projecting into the barrel in obstructing relation to said leaf spring for locking the sleeve and the hammer together for movement away from said plunger, and

means within the barrel engageable by said i leaf spring for holding the latterout of engagement with said stop element, said means being adjustable whereby its degree of-projection toward said leaf spring may be varied. 

